Inductor coil



Del 1931- P. H. BRAcE 1,334,445

' INDUCTOR COIL Filed April 2o, 1929 w l V.

INVENTOR Por/Er A( Brace.

WMM

' ATTORNEY Patented Dec. 1, 19371 PATENT OFFICE A PORTEREBRAGEQOE WILKrNsi?une,V rENNsYLvANIA, .Assieivon ro WESTINGHOUSE Y Emicrania: a MANUFACTURING ooMrfANY, A oonroimrron or` PENNsxLvAnLIA INDUCTOR con.'

'Application led CApril* 20,

'videj a single highly efficient cooling lmeans for a plurality of conductor portions which shall embody means for reducing inductive` l heating of such portionsi In'practiclng my invention, I provid'ean inductor coil comprising a plurality ofturns of current-carrying'portions of solid metal,

' electric-insulating material therebetween and al single coolingmeans therefor comprising a fluid-traversed conduit` of metal having' a. fin portion" extending laterally thereof and in operative engagement with*` a partof the peripheral surface of theconf Y ductor portions.

The lfiniportion is preferably laterallyv slotted'in order to reduce the eddy-current loss therein.

Referring to the single sheetpof drawings,

Figure 1 is a view,fin vertical section, through an inductor coil embodying my 1nvention, and a Crucible surrounded by.'1t.-

Fig. 2 isl a view, in'sectional perspective,` on an enlarged scale, ofa portion of the inductor coil of Fig. 1.A l

Fig. 3 is a sectional perspective view 'of an inductor coil of modified form embodying my invention, and f f Figs. 4 and 5'are 'sectional perspective views of still other modifications of inductor coils embodying my invention.

illustrated aninductor coil llas embodying a plurality of .layers locatedv in .spaced rela# tion around' a cruciblelQ, each layer comprising aiplurality of -rl'aterally-superposed individual turns of a solidco'nductor113..y The iconductor lmaybe of anydimension and shape but I prefer to make it oblongin lateral section although, of course, it mayl be of square section! Y y.

l Each layer comprises anyssuitable --or der.

jsired number ofvturns, here shown-.as ;5 in

'coils may be employed. l The individual turns of each 1929. j serial,l No. 356,706.4l p

number. In winding the' perspective layers, it, isobvio,u`sthat it is necessary to begin with the. inner turn, then to wind outwardly to form reach layer after which vtwo adjacent layersareconnected at some suitable point,

as by abridging member 14, connectedto the` n turnsof `the adjacent layers, and any suit-,g

able and desired method of winding thel y i layerlare sepa?l rated by electricfinsulating material 15 of, any suitable or desired kind, and thev adjacent larV portion" 17. Thezfin .18 `is made relatively thinand of such width laterally of the'member 16, as to be substantially co-extensive with thethickness or the Aradial extent of each of the layers of the induotor coil. Strips .19 y

of electricinsulating material are located between the conductor portions 13 and the 1in r 18,- asis clearly shownl in Fig. 2 of the drawings@y n y i It is appar nt that eddy currents will be induced in thegfin 18 of the metallic element 16-and I, therefore, provide'means for reduc# ing the eddy current lossescaused therein by v the alternating-current flux generated bythe In F igs.` 1 and 2 of thedrawings,` I have.k

alternating currentr traversing the inductor coil, this means embodying a plurality of lat erally extendingslotsQl in the fins 18. `Any pairs of layers of the induetorcoilare spaced,` i

desired number of slots 21 may be provided inthe fins 18,'whereby it is possible to greatly reduce the eddy7 current losses in that portion of the `cooling-means. I prefer to make the coolingmeans 16 of a metalthat is" non-cor# rosive and of relatively high electrical Vrcsistance such as an alloy of copper'andniclel,` usually known'asMonelLmetaL or a ferrous lalljoy, having a relativelyhigh electrical resistance and a relatively high resistance to corrosion.

It may be noted that the outside diameter of the tubular portion 17 may be made substantially the same as the space occupied by two adjacent layers, both of which are cooled by the single cooling means. I have found, that when the conduit portion 17 is traversed by a suitable cooling iuid, such as water, a highly efficient heat-withdrawing means is provided whereby heat is drawn from the fin 18 and, therefore, from the conductor portions 13.

A relatively thin annular or helical strip of electric-insulating material 22 is provided which may either be in one piece or inv a plurality of pieces and is located between adjacent pairs of layers in the manner shown in Fig. 1 of the drawings.

Any suitable means (not shown) for anchoring the inductor-coil layers may be provided but 1s-this forms no particular part of my invention, I have not deemed it necessary Vto illustrate and describe the same in detail.

I have'illustrated, schematically only, terminals 23 and 24 for the current-traversed conductor portions and I have illustrated end portions 26 and 27 for ythe fluid-traversed cooling means, and, more particularly, Vfor the conduit portion 17, in order to permit of connecting therewith a suitable source of supply of a cooling fluid, such as water.

Referring more particularly to Fig. 3 of the drawings, I have there illustrated one modification of a plurality of conductor portions cooperating with a single cooling means. Conductor portions 28 are separated by strips 29 of electric-insulating material and the conductor portions and the electric-insulating material portions are located within va cooling means embodying a conduit portion 31 and two co-extensive fins 32 and 33 eXtending laterally from the conduit portion 31 and integral therewith. Slots 34 and 36 are provided in the respective portions 32 and 33 to extend laterally from the portion 31 and are of substantially the same length as the thickness of the assembled members 28 and 29. Strips 37, of electric-insulating material are located between the lins 32 and 33 and the conductor portions 28. The conductor portions 28 may be electrically connected in parallel-circuit relation in order to provide a relatively large area of metal conductor to be traversed by an electric current of relatively low voltage.

Referring more particularly to Fig. 4 of the drawings, I have there illustrated a structure in which the current-conducting portions and the'cooling means are substantially integral. A metallic element 38, of elongated form and of substantially rectangular shape in lateral section, embodies a conduit por tion 39 and current-conducting portions 41 which vare spaced from each other either by air or by a suitable electric-insulating material located in the slots between them. The slots extend from one edge of the initially solid portion of the member 38 to within a short distance of the other face in order to provide an integral portion 42 to connect all of the portions 41 to the cooling portion 3f). A plurality of slots 43 extend laterally in the portion 42, the depth being just sufiicent to meet the other slots separating the fportions 41.

Referring more particularly to Fig. 5 of the drawings, I havel there illustrated a composite element 44 comprising a cooling portion 46, of substantially tubular shape, and an initially solid metal portion 47 which is provided with a plurality of longitudinally extending slot-s 48 extending from one face thereof and a plurality of intermediate spaced longitudinally-extending slots 49 extending from the other face. The general effect is that of a zig-Zag conductor, the integral por tions of which are separated either by air or by some other electrical insulating material, a small web portion only connecting the current-conducting portions to the cooling portion thereof.

Laterally-eXtending slots 51 and 52 are provided at spaced intervals in each face in order to reduce the eddy-current losses in the otherwise integral portions constituting the web portions hereinbefore mentioned.

It is obvious that the structure shown in Figs. 1 and 2 provides a plurality of turns of conductor per layer, while the structures shown in Figs. 3 to 5 inclusive, can be used only as a plurality of parallel-connected conductor portions or, in other' words, each layer will comprise a` single turn only and be therefore, better adapted to a low-voltage source of supply. However, it is obvious that changes may be made in the dimensions of the current-conducting portions and suitable and cofoperating changes in rthe cooling means in order to adapt the structure to any suitable or desired dimensions of material to be heated, such as a crucible or a mass of metal, as well as to adapt. it to a convenient source of supply of elect-ric energy.

The device embodying my invention thus provides an inductor-coil lstructure in which a plurality of conductor portions, be they connected in series-circuit relation or in parallel-circuit relation, are cooled by a single highly eiiicient cooling means, which is of such shape as to provide a fiuid-traversed portion and a-solid portion in operative engagement with a part of the surface of the conductor portions, in order that a highly eicient Withdrawal of the heat from the conductor portionsmay be effected. A part of the structure of the cooling means is further provided with means for reducing the eddycurrent loss therein-in order that the losses in the induetor-coil structure may be kept at as low a value as is practicable.

Since various modifications may be made in Y the device embodying my invention without departing 'from the spirit and scope thereof,

v l desire that only such limitations shall be placed thereon as are imposedby the prior art or are set forth in the appended claims.

l claim as my invention:

1. An inductor coil comprising a plurality of adj acently-located current-transversedl conductor portions of solid metal, electric-insulating material therebetween, a single cooling means for all of said conductor portions,`

said means embodying a strip portion of Inetal co-eXtensive with the conductor ,portion and in operative engagement with a part of the surface of each of said conductor portions, y a conduit portion integral with the strip portion and electric-insulating material between the strip portion and the conductorportions and means embodied inthe strip portion of the cooling means for reducing eddy-current losses therein.

, 5 2. An inductor coil comprising a plurality of adjacently-looated current-traversed conductor portions of solid metal, electric-insulating material therebetween, a single cooling means for all of said conductor portions,

said means embodying a strip portion of metal cfa-extensive with the conductor portion and in operative engagement with a part of the surface of each or' said conductor portions and means embodied in the strip portion of the cooling means for reducing eddy-current losses therein. .y y

ln testimony whereof, I have hereunto subl scribed myname this 17thday of April, 1929.

. PORTER H. BRACE. 

